Methods for Operating Dishwasher Appliances Having Energy Recovery Features

ABSTRACT

Dishwasher appliances and method for operating dishwasher appliances are provided. A method includes executing a wet cycle, wherein a heating unit and a fan of a desiccant assembly are active during the wet cycle. The desiccant assembly includes the heating unit, the fan, and a desiccant module and is in fluid communication with a wash chamber of the dishwasher appliance. The method further includes executing a delay period, the delay period occurring for a predetermined time period between the wet cycle and a dry cycle, wherein the heating unit and the fan are inactive during the delay period. The method further includes draining liquid from the wash chamber after the delay period, and executing a dry cycle, wherein the fan is active and the heating unit is inactive during the dry cycle.

FIELD OF THE INVENTION

The present disclosure relates generally to methods for operatingdishwasher appliances, and more particularly to methods for operatingdishwasher appliances which utilize desiccants to recover energy duringoperation.

BACKGROUND OF THE INVENTION

Modern dishwashers typically include a wash chamber where e.g.,detergent, water, and heat can be applied to clean food or othermaterials from dishes and other articles being washed. Various cyclesmay be included as part of the overall cleaning process. For example, atypical, user-selected cleaning option may include a wash cycle andrinse cycle (referred to collectively as a wet cycle), as well as adrying cycle. A pre-wash cycle may also be included as part of the wetcycle, and may be automatic or an option for particularly soiled dishes.

Presently, many known dishwasher appliances utilize venting arrangementsto vent moist air during the drying cycle, in order to facilitatedrying. New air is drawn into the dishwasher appliance as the moist airis vented from the dishwasher appliance to the exterior environment.Such approach, however, can be problematic. For example, venting themoist air during the drying cycle can add moisture and heat to thesurrounding environment, such as the kitchen or other room where thedishwasher appliance is located. Additionally, the air drawn into thedishwasher appliance from the surrounding environment can, in somecases, potentially be dirty or include undesirable particles, etc.

More recently, attempts have been made to recirculate air within thedishwasher appliances in order to reduce or avoid the above discusseddisadvantages, and to generally recover the associated energy. Forexample, adsorbent assemblies have been utilized in dishwasherappliances in attempts to remove moisture during operation. However,known adsorbent assemblies and the methods in which they are utilizedhave generally proved to be relatively inefficient.

Accordingly, improved methods for operating dishwasher appliances aredesired in the art. In particular, methods which provide improved airrecirculation and energy recovery during operation would beadvantageous.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In accordance with one embodiment of the present disclosure, a methodfor operating a dishwasher appliance is provided. The method includesexecuting a wet cycle, wherein a heating unit and a fan of a desiccantassembly are active during the wet cycle. The desiccant assemblyincludes the heating unit, the fan, and a desiccant module and is influid communication with a wash chamber of the dishwasher appliance. Themethod further includes executing a delay period, the delay periodoccurring for a predetermined time period between the wet cycle and adry cycle, wherein the heating unit and the fan are active during thedelay period. The method further includes draining liquid from the washchamber after the delay period, and executing a dry cycle, wherein thefan is active and the heating unit is inactive during the dry cycle.

In accordance with another embodiment of the present disclosure, amethod for operating a dishwasher appliance is provided. The methodincludes executing a wet cycle, wherein a heating unit and a fan of adesiccant assembly are active during the wet cycle. The desiccantassembly includes the heating unit, the fan, and a desiccant module andis in fluid communication with a wash chamber of the dishwasherappliance. The method further includes executing a delay period, thedelay period occurring for a predetermined time period between the wetcycle and a dry cycle, wherein the heating unit and the fan are inactiveduring the delay period. The method further includes draining liquidfrom the wash chamber after the delay period, and executing a dry cycle,wherein the fan is active and the heating unit is inactive during thedry cycle.

In accordance with another embodiment of the present disclosure, adishwasher appliance is provided. The dishwasher appliance includes acabinet defining an interior, a tub disposed within the interior anddefining a wash chamber for the receipt of articles for cleaning, a sumpfor collecting liquid from the chamber, a drain conduit for drainingliquid from the tub, and a fluid circulation conduit for circulatingliquid in the tub. The dishwasher appliance further includes aclosed-loop adsorption assembly in fluid communication with the washchamber, the closed-loop adsorption assembly including a desiccantassembly, the desiccant assembly comprising a desiccant module, aheating unit and a fan.

In some embodiments, the dishwasher appliance further includes a tubfan, the tub fan positioned within the interior and configured toactively flow air from the interior into the wash chamber.

In some embodiments, the dishwasher appliance further includes acontroller, the controller in communication with the heating unit andthe fan and configured for executing a wet cycle, wherein the heatingunit and the fan are active during the wet cycle; executing a delayperiod, the delay period occurring for a predetermined time periodbetween the wet cycle and a dry cycle, wherein the heating unit and thefan are active during the delay period; draining liquid from the washchamber after the delay period; and executing a dry cycle, wherein thefan is active and the heating unit is inactive during the dry cycle.

In some embodiments, the dishwasher appliance further includes acontroller, the controller in communication with the heating unit andthe fan and configured for executing a wet cycle, wherein the heatingunit and the fan are active during the wet cycle; executing a delayperiod, the delay period occurring for a predetermined time periodbetween the wet cycle and a dry cycle, wherein the heating unit and thefan are inactive during the delay period; draining liquid from the washchamber after the delay period; and executing a dry cycle, wherein thefan is active and the heating unit is inactive during the dry cycle.

In some embodiments, the controller is further in communication with thetub fan.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 provides a front, perspective view of a dishwasher appliance inaccordance with one embodiment of the present disclosure;

FIG. 2 provides a side, cross-sectional view of a dishwasher appliancein accordance with one embodiment of the present disclosure;

FIG. 3 provides a schematic view of various components of a dishwasherappliance, including a closed-loop adsorption assembly, in accordancewith one embodiment of the present disclosure;

FIG. 4 provides a side cross-sectional view of components of aclosed-loop adsorption assembly in accordance with one embodiment of thepresent disclosure;

FIG. 5 provides a side cross-sectional view of components of aclosed-loop adsorption assembly in accordance with another embodiment ofthe present disclosure;

FIG. 6 provides a cross-sectional profile view of a desiccant assemblyof a closed-loop adsorption assembly in accordance with one embodimentof the present disclosure;

FIG. 7 provides a cross-sectional profile view of a desiccant assemblyof a closed-loop adsorption assembly in accordance with anotherembodiment of the present disclosure;

FIG. 8 is a chart illustrating operation of various components of adishwasher appliance in accordance with one embodiment of the presentdisclosure;

FIG. 9 is a chart illustrating operation of various components of adishwasher appliance in accordance with another embodiment of thepresent disclosure; and

FIG. 10 is a chart illustrating operation of various components of adishwasher appliance in accordance with another embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

FIGS. 1 and 2 depict an exemplary domestic dishwasher appliance 100 thatmay be configured in accordance with aspects of the present disclosure.For the particular embodiment of FIG. 1, the dishwasher appliance 100includes a cabinet 102 that defines an interior 103. A tub 104 isdisposed in the interior 103. Tub 104 defines a wash chamber 106.Chamber 106 is configured for the receipt of articles for cleaning, suchas dishes, cups, utensils, etc. The tub 104 includes a front opening(not shown) and a door 120 hinged at or near its bottom side wall 122for movement between a normally closed vertical position (shown in FIGS.1 and 2), wherein the wash chamber 106 is sealed shut for washingoperation, and a horizontal open position for loading and unloading ofarticles from the dishwasher appliance 100. Latch 123 is used to lockand unlock door 120 for access to chamber 106.

Upper and lower guide rails 124, 126 are mounted on tub side walls 128and accommodate roller-equipped rack assemblies 130 and 132. Each of therack assemblies 130, 132 may be fabricated into lattice structuresincluding a plurality of elongated members 134 (for clarity ofillustration, not all elongated members making up assemblies 130 and 132are shown in FIG. 2). Each rack 130, 132 is adapted for movement betweenan extended loading position (not shown) in which the rack issubstantially positioned outside the wash chamber 106, and a retractedposition (shown in FIGS. 1 and 2) in which the rack is located insidethe wash chamber 106. This is facilitated by rollers 135 and 139, forexample, mounted onto racks 130 and 132, respectively. A silverwarebasket (not shown) may be removably attached to rack assembly 132 forplacement of silverware, utensils, and the like, that are otherwise toosmall to be accommodated by the racks 130, 132.

The dishwasher appliance 100 further includes a lower spray-arm assembly144 that is rotatably mounted within a lower region 146 of the washchamber 106 and above a tub sump portion 142 so as to rotate inrelatively close proximity to rack assembly 132. A mid-level spray-armassembly 148 is located in an upper region of the wash chamber 106 andmay be located in close proximity to upper rack 130. Additionally, anupper spray assembly 150 may be located above the upper rack 130.

The lower and mid-level spray-arm assemblies 144, 148 and the upperspray assembly 150 are fed by a fluid circulation conduit 152 forcirculating water and dishwasher fluid (generally referred to as liquid)in the tub 104. A first pump 154, which may for example be located in amachinery compartment 140 located below the bottom sump portion 142 ofthe tub 104, may flow liquid from sump 160 to and through the fluidcirculation conduit 152. Each spray-arm assembly 144, 148 includes anarrangement of discharge ports or orifices for directing washing liquidonto dishes or other articles located in rack assemblies 130 and 132.The arrangement of the discharge ports in spray-arm assemblies 144, 148provides a rotational force by virtue of washing fluid flowing throughthe discharge ports. The resultant rotation of the lower spray-armassembly 144 provides coverage of dishes and other dishwasher contentswith a washing spray.

A drain conduit 170 may additionally be provided for draining water anddishwasher fluid (generally referred to as liquid) from the tub 104. Asecond pump 172, which may for example be located in the machinerycompartment 140, may flow liquid from sump 160 to and through drainconduit 170. This liquid may be flowed from the appliance 100 generally,such as to the plumbing of a structure in which the appliance 100 isprovided.

Dishwasher appliance 100 may further include a tub fan 180. Tub fan 180may facilitate air flow within the wash chamber 106 at various timesduring operation of the dishwasher appliance 100. The tub fan 180 may bepositioned within the interior 103, and may in some embodiments bepositioned at least partially or entirely in the wash chamber 106. Forexample, tub fan 180 may be disposed in the wash chamber 106 proximate awall of the tub 104, such as an upper wall (along a vertical direction)as illustrated. The tub fan 180 may, when activated, actively flow airwithin the wash chamber 106 and over articles disposed therein.

The dishwasher 100 is further equipped with a controller 137 to regulateoperation of the dishwasher 100. The controller may include a memory andmicroprocessor, such as a general or special purpose microprocessoroperable to execute programming instructions or micro-control codeassociated with a cleaning cycle. The memory may represent random accessmemory such as DRAM, or read only memory such as ROM or FLASH. In oneembodiment, the processor executes programming instructions stored inmemory. The memory may be a separate component from the processor or maybe included onboard within the processor.

The controller 137 may be positioned in a variety of locationsthroughout dishwasher 100. In the illustrated embodiment, the controller137 may be located within a control panel area 121 of door 120 as shown.In such an embodiment, input/output (“I/O”) signals may be routedbetween the control system and various operational components ofdishwasher 100 along wiring harnesses that may be routed through thebottom side wall 122 of door 120. Typically, the controller 137 includesa user interface panel 136 through which a user may select variousoperational features and modes and monitor progress of the dishwasher100. In one embodiment, the user interface 136 may represent a generalpurpose I/O (“GPIO”) device or functional block. In one embodiment, theuser interface 136 may include input components, such as one or more ofa variety of electrical, mechanical or electro-mechanical input devicesincluding rotary dials, push buttons, and touch pads. The user interface136 may include a display component, such as a digital or analog displaydevice designed to provide operational feedback to a user. The userinterface 136 may be in communication with the controller 137 via one ormore signal lines or shared communication busses.

Controller 137 may further be in communication with various component ofthe appliance 100, such as the first and second pumps 154, 172, tub fan180 and a heating unit and a fan of a desiccant assembly as discussedherein. Accordingly, controller 137 may send signals to these variouscomponents to activate and deactivate the components as required duringoperation of the dishwasher appliance 100 in a wash cycle.

In general, dishwasher appliance 100 may utilize a variety of cycles towash and, optionally, dry articles within chamber 106. For example, awet cycle is utilized to wash articles. The wet cycle may include a mainwash cycle and a rinse cycle, as well as an optional pre-wash cycle.During each such cycle, water or another suitable liquid may be utilizedin chamber 106 to interact with and clean articles therein. Such liquidmay, for example, be directed into chamber 106 from lower and mid-levelspray-arm assemblies 144, 148 and the upper spray assembly 150, such asvia fluid circulation conduit 152 and pump 154. The liquid mayadditionally mix with, for example, detergent or other various additiveswhich are released into the chamber during various sub-cycles of the wetcycle.

For example, during a wet cycle, a pre-wash cycle may additionally beexecuted. In the pre-wash cycle, water is directed into chamber 106,with no detergent (other than detergent remnants in the chamber 106 froma previous wet cycle) being mixed with the water. After the pre-washcycle, a wash cycle may be executed. In the wash cycle, water isdirected into the chamber 106 and mixed with detergent. After the washcycle, a rinse cycle may be executed. In the rinse cycle, water isdirected into the chamber 106, with no additional detergent (other thandetergent remaining in the chamber 106 due to the wash cycle) beingmixed with the water. Notably, liquid within the wash chamber 106 may bedrained between the pre-wash cycle and the wash cycle, and between thewash cycle and the rinse cycle. Drain conduit 170 and second pump 172may be utilized for such drainage. Liquid within the wash chamber 106may additionally be drained after the rinse cycle, such as via drainconduit 170 and second pump 172. Such drainage may, as discussed herein,occur after a delay period is executed as discussed herein.

A dry cycle may be utilized to dry articles after washing in the wetcycle. During a drying cycle, for example, moisture within chamber 106may be adsorbed as discussed herein to facilitate drying of the articleswithin the chamber 106. In generally, no liquid is sprayed or otherwiseproduced or directed into the wash chamber 106 during the drying cycle.

It should be appreciated that the invention is not limited to anyparticular style, model, or other configuration of dishwasher, and thatthe embodiment depicted in FIGS. 1 and 2 is for illustrative purposesonly. For example, instead of the racks 130, 132 depicted in FIG. 1, thedishwasher 100 may be of a known configuration that utilizes drawersthat pull out from the cabinet and are accessible from the top forloading and unloading of articles. Other configurations may be used aswell.

Referring now to FIGS. 3 through 7, dishwasher appliances 100 accordingto the present disclosure may further include various components whichfacilitate improved air recirculation and energy recovery duringoperation of the appliance 100. In particular, dishwasher appliances 100may utilize desiccants to adsorb moisture, in particular during thedrying cycle, and desorb such moisture during the wet cycle. Suchadsorption and desorption may reduce or eliminate the need to vent airfrom the dishwasher appliance 100 during operation. Further, desorptionmay facilitate fluid heating within the dishwasher appliance 100, thusproviding improved efficiency by causing the dishwasher appliance 100 torequire less heating. Notably, in exemplary embodiments, no heatingelements are required in the wash chamber 106, with the only heatingelements required being components of the adsorption assembly whichprovides such advantages as discussed herein.

As illustrated, a dishwasher appliance 100 in accordance with thepresent disclosure may include a closed-loop adsorption assembly 200.The closed-loop adsorption assembly 200 is in fluid communication withthe wash chamber 106, such that fluid is flowable to the adsorptionassembly 200 from the wash chamber 106 and to the wash chamber 106 fromthe adsorption assembly 200. Adsorption assembly 200 thus may include aninlet 202 defined in the tub 104 and an outlet 204 defined in the tub104. As discussed herein, adorption and desorption of moisture mayadvantageously occur within adsorption assembly 200.

In particular, adsorption assembly 200 may further include a desiccantassembly 210 in which adsorption and desorption of moisture may occur.Desiccant assembly 210 may be in fluid communication with the inlet 202and the outlet 204. For example, in some embodiments, desiccant assembly210 may be directly connected to the inlet 202 and/or outlet 204. Inother embodiments, conduits may extend between the inlet 202 and/oroutlet 204 and the desiccant assembly 210. As shown, assembly 200 mayfurther include an inlet conduit 212 extending between the inlet 202 andthe desiccant assembly 210 for flowing fluid from the wash chamber 106to the desiccant assembly 210 (such as to an inner passage thereof asdiscussed herein). As further shown, assembly 200 may further include anoutlet conduit 214 extending between the desiccant assembly 210 and theoutlet 204 for flowing fluid from the desiccant assembly 210 (such as anouter passage thereof as discussed herein) to the wash chamber 106.

In exemplary embodiments as shown, the desiccant assembly 210, as wellas inlet and outlet conduits 212, 214, may be disposed in the interior103 (but exterior to the tub 104).

Desiccant assembly 210 generally includes various passages through whichfluid may flow. As shown, desiccant assembly 200 may include an innerpassage 222, an intermediate passage 224, and an outer passage 226. Theinner passage 222 may receive fluid from the wash chamber 106.Accordingly, inner passage 222 may be directly connected to the inlet202 or to the inlet conduit 212, such that fluid flows from the inlet202 and/or inlet conduit 212 into the inner passage 222. Intermediatepassage 224 may surround the inner passage 222, and outer passage 226may surround the intermediate passage 226. Fluid received in the innerpassage 224 may be flowable through the intermediate passage 224 to theouter passage 226. Further, wash chamber 106 may receive fluid from theouter passage 226. Accordingly, outer passage 226 may be directlyconnected to the outer 204 or to the outlet conduit 214, such that fluidflow from the outer passage 226 through the outlet conduit 214 and/oroutlet 204.

In exemplary embodiments, desiccant assembly 210 may include variousconduits which define the various passages thereof. For example,desiccant assembly 210 may further include an inner conduit 232 whichdefines the inner passage 222, an intermediate conduit 234 whichsurrounds the inner conduit 222 and defines the intermediate passage224, and an outer conduit 236 which surrounds the intermediate conduit234 and defines the outer passage 236. In exemplary embodiments asshown, the inner conduit 232 and the intermediate conduit 234 areperforated, and thus define perforations 233, 235 respectivelytherethrough, through which fluid can flow.

It should be noted that in some embodiments the inner conduit 232 can bean integral extension of the inlet conduit 212 and/or the outer conduit236 can be an integral extension of the outlet conduit 214. In somealternative embodiments, the inner conduit 232 can be a separatecomponent that is coupled to the inlet conduit 212 and/or the outerconduit 236 can be a separate component that is coupled to the outletconduit 214.

As shown, as desiccant module 240 is disposed in the intermediatepassage 224, such that the desiccant module 240 generally surrounds theinner passage 222. Thus, fluid flowing from the inner passage 222through the intermediate passage 224 to the outer passage 226 flowsthrough the desiccant module 240 while flowing through the intermediatepassage 224. This facilitates adsorption and desorption of moisture bythe desiccant module 240.

In exemplary embodiments, the desiccant module 240 may include agranular desiccant 242, as shown. In exemplary embodiments, the granulardesiccant 242 may be zeolite. Alternatively, however, the desiccant maybe activated charcoal, calcium sulfate, calcium chloride, or anothersuitable molecular sieve, or any other suitable material, etc. Inalternative embodiments, the desiccant module 240 may include aplurality of desiccant-coated plates (not shown). In exemplaryembodiments, the desiccant coating the plates may be zeolite.Alternatively, however, the desiccant may be activated charcoal, calciumsulfate, calcium chloride, or another suitable molecular sieve, or anyother suitable material, etc. The plates themselves may be formed fromany suitable material, such as a suitable metal, polymer, ceramic, etc.

Adsorption assembly 200 may further include various components tofacilitate adsorption and desorption as required. For example,adsorption assembly 200 may include a fan 250. The fan 250 may encouragefluid flow through the desiccant assembly 210 and adsorption assembly200 generally. In some embodiments as shown in FIG. 4, fan 250 isdisposed downstream of the desiccant assembly 210 (relative to the flowdirection of fluid through the adsorption assembly 200), such as withinthe outlet conduit 214. In other embodiments as shown in FIG. 5, fan 250is disposed upstream of the desiccant assembly 210 (relative to the flowdirection of fluid through the adsorption assembly 200), such as withinthe inlet conduit 212. In still other embodiments, fan 250 may bedisposed within the desiccant assembly 210, such as in inner passage222.

Adsorption assembly 200 may further include a heating unit 255, whichmay be included in the desiccant assembly 210. The heating unit 255 mayinclude one or more heating elements 257, such as two (as shown in FIG.6), three, four (as shown in FIG. 7) or more. In some embodiments, twoor four heating elements 257 may be desirable due to the rectangularcross-sectional profile of the various passages 222, 224, 226, asdiscussed herein. In exemplary embodiments, the heating unit 255, suchas the heating elements 257 thereof, may be disposed within the innerpassage 222. These embodiments are particularly advantageous because asubstantial portion of the heat emitted by the heating unit 255 istrapped by the desiccant module 240. Accordingly, these embodiments areparticularly energy efficient. In alternative embodiments, however, theheating unit 255, such as the heating elements 257 thereof, may forexample be disposed within the outer passage 226.

Each heating element 257 may extend through the desiccant assembly 210between the inlet of the desiccant assembly 210 (on the upstream sidethereof) and the outlet of the desiccant assembly 210 (on the downstreamside thereof). In some embodiments, the heating elements 257 may haveconstant wattages therethrough between the inlet side and the outletside thereof. Alternatively, however, the heating elements 257 may havevariable wattages therethrough between the inlet side and the outletside thereof. For example, the wattage of a heating element 257 may begreater at the inlet side and may decrease from the inlet side to theoutlet side, to reduce or prevent temperature gradients in the desiccantmodule 240 along the length thereof between the inlet side and theoutlet side.

Referring now to FIGS. 6 and 7, the passages 222, 224, 226 of thedesiccant assembly 210 may in exemplary embodiments each have agenerally rectangular cross-sectional profile. In further exemplaryembodiments, the rectangle may be a square. Square cross-sectionalprofiles are illustrated in FIG. 7, while other rectangularcross-sectional profiles are illustrated in FIG. 6. Such cross-sectionalprofiles may advantageously facilitate efficient fluid flow through thepassages 222, 224, 226, in particular relative to oval or circularcross-sectional profiles. For example, oval or circular cross-sectionalprofiles may encourage generally helical flow patterns for fluid throughthe passages 222, 224, 226, while rectangular cross-sectional profilesencourage the patterns to be relatively less helical and more axial.Accordingly the fluid flow using such rectangular cross-sectionalprofiles can be relatively more efficient. It should be understood,however, that the present disclosure is not limited to rectangularcross-sectional profiles. Rather, any suitable profiles, including ovalor circular cross-sectional profiles, are within the scope and spirit ofthe present disclosure.

Referring again to FIGS. 4 and 5, the intermediate passage 224 (whichhouses the desiccant assembly 240) has a thickness 260 as illustrated.In exemplary embodiments, the thickness 260 is relatively small, thusencouraging efficient fluid flow therethrough and reducing restrictionscaused by the desiccant assembly 240. For example, in some embodiments,a maximum thickness 260 of the intermediate passage 224 is betweenapproximately 15 millimeters and approximately 50 millimeters, such asbetween approximately 20 millimeters and approximately 40 millimeters.

Intermediate passage 224 may further have a length 262. The length 262may in exemplary embodiments be sized relative to the thickness 260 toensure adequate adsorption and desorption capabilities for the desiccantassembly 240 disposed in the intermediate passage 224. For example, insome embodiments, a maximum length 262 of the intermediate passage 224is between approximately 200 millimeters and approximately 400millimeters, such as between approximately 250 millimeters andapproximately 350 millimeters.

It should be understood that the present disclosure is not limited tothe above-disclosed embodiments of adsorption assembly 200 and desiccantassembly 210. Rather, any suitable adsorption assembly 200 whichutilizes a desiccant assembly 210, and any suitable desiccant assembly210 which utilizes a desiccant module 240, a heating unit 255 and/or afan 250 is within the scope and spirit of the present disclosure.

Referring now to FIGS. 8 through 10, the present disclosure is furtherdirected to methods for operating dishwasher appliances 100. Inexemplary embodiments, the various steps of methods as discussed hereinmay be performed by controller 137. Methods in accordance with thepresent disclosure facilitate efficient use of the adsorption assembly200 and desiccant assembly 210 to promote improved heating of waterduring the wet cycle and improved drying of articles during the drycycle.

For example, a method 300 in accordance with the present disclosure mayinclude the step 310 of executing a wet cycle 312. Wet cycle 312 mayinclude, for example, one or more of a pre-wash cycle 314, a wash cycle316 and a rinse cycle 318. During the wet cycle 312, the heating unit255 and the fan 250 may be active. When active, the heating unit 255 maygenerate heat and the fan 250 may actively flow fluid therethrough. Wheninactive, the heating unit 255 may not generate heat and the fan 250 maynot actively flow fluid therethrough. Further, the tub fan 180 may beinactive during the wet cycle 312. When active, the tub fan 180 mayactively flow fluid therethrough. When inactive, the tub fan 180 may notactively flow fluid therethrough.

For example, in some embodiments, as illustrated in FIGS. 8 and 10, theheating unit 255 and the fan 250 may be continuously active during theentire wash cycle 316 and the entire rinse cycle 318. In otherembodiments, as illustrated in FIG. 9, the heating unit 255 and the fan250 may be active during only a portion of the wash cycle 316 and aportion of the rinse cycle 318. For example, the heating unit 255 andfan 250 may be active during a first portion 316′ of the wash cycle 316,inactive during a second portion 316″ of the wash cycle 316, inactiveduring a first portion 318′ of the rinse cycle 318, and active during asecond portion 318″ of the rinse cycle 318. While in some embodiments asillustrated in FIGS. 8 and 9 the heating unit 255 and the fan 250 may becontinuously inactive during the prewash cycle 314, in other embodimentsas illustrated in FIG. 10 the heating unit 255 and the fan 250 may becontinuously active during the prewash cycle 314. Accordingly, in someembodiments as illustrated in FIG. 10, the heating unit 255 and the fan250 may be continuously active during the entire wet cycle 312, while inother embodiments as illustrated in FIGS. 8 and 9 the heating unit 255and the fan 250 may be active during only a portion of the wet cycle312.

Notably, in exemplary embodiments as illustrated in FIGS. 8 through 10,tub fan 180 may be continuously inactive during the entire wet cycle.Alternatively, tub fan 180 may be inactive during only a portion of thewet cycle.

Method 300 may further include, for example, the step 320 of executing adelay period 322. The delay period 322 may occur after the wet cycle 312is executed in accordance with step 310 and before fluid is drained fromwash chamber 106 in accordance with a step 330 as discussed herein, aswell as before a dry cycle 342 is executed in accordance with step 340as discussed herein. Further, in exemplary embodiments, no liquid may bedrained from the wash chamber 106 after the wet cycle 312 is executedand before the delay period 322 is executed. Accordingly, liquidprovided to wash chamber 106 during the final sub-cycle of step 310,typically the rinse cycle 318, may remain in the wash chamber 106 duringthe delay period 322. Further, no additional liquid may be provided tothe wash chamber 106 during the step 320.

Delay period 322 may occur for a predetermined time period. In exemplaryembodiments, the predetermined time period may be between 1 minute and15 minutes, such as between 2 minutes and 10 minutes, such as between 3minutes and 8 minutes, such as between 4 minutes and 7 minutes.

In some embodiments, as illustrated in FIGS. 8 and 9, the heating unit255 and fan 250 may be active during the delay period 322. For example,in exemplary embodiments, the heating unit 255 and the fan 250 may becontinuously active during the entire delay period 322. In alternativeembodiments, as illustrated in FIG. 10, the heating unit 255 and fan 250may be inactive during the delay period 322. For example, in exemplaryembodiments, the heating unit 255 and the fan 250 may be continuouslyinactive during the entire delay period 322.

As illustrated in FIGS. 8, 9 and 10, in exemplary embodiments, the tubfan 180 may be active during the delay period 322. For example, the tubfan 180 may be continuously active during the entire delay period 322.

Method 300 may further include, for example, the step 330 of drainingliquid from the wash chamber 106. Such step 330 may occur after thedelay period 322 is executed in accordance with step 320. Further, asdiscussed above, liquid provided to wash chamber 106 during the finalsub-cycle of step 310, typically the rinse cycle 318, may remain in thewash chamber 106 during the delay period 322 and until it is drained inaccordance with step 330. In exemplary embodiments, as illustrated inFIGS. 8, 9 and 10, the heating unit 255 and the fan 250 may be inactiveduring the step 330 of draining liquid from the wash chamber 106. Forexample, the heating unit 255 and the fan 250 may be continuouslyinactive during the entire step 330 of draining liquid from the washchamber 106. Further, as illustrated in FIGS. 8, 9 and 10, in exemplaryembodiments, the tub fan 180 may be active during the step 330 ofdraining liquid from the wash chamber 106. For example, the tub fan 180may be continuously active during the entire step 330 of draining liquidfrom the wash chamber 106.

Method 300 may further include, for example, the step 340 of executing adry cycle 342. Dry cycle 342 may occur after execution of the delayperiod 322 in accordance with step 320 and after liquid has been drainedfrom the wash chamber 106. In exemplary embodiments as illustrated inFIGS. 8, 9 and 10, the heating unit 255 may be inactive during the drycycle 342. For example, the heating unit 255 may be continuouslyinactive during the entire dry cycle 342. Additionally, the fan 250 maybe active during the dry cycle 342. For example, the fan 250 may becontinuously active during the entire dry cycle 342. Further, the tubfan 180 may be active during the dry cycle 342. For example, the tub fan180 may be continuously active during the entire dry cycle 342.

As discussed, in exemplary embodiments, controller 137 may be inoperable communication with various components of the dishwasherappliance 100, such as the pumps 154, 172, the tub fan 180, the heatingunit 255 and the fan 250. Controller 137 may activate and deactivatesuch components as required and in accordance with the various methodsteps as discussed herein. Such operation may facilitate efficient andadvantageous adsorption and regeneration/desorption of the desiccant toprovide improved dishwasher appliance 100 operation. For example, whenthe heating unit 255 is active, the relatively higher temperatureswithin the desiccant assembly 210 may facilitate regeneration anddesorption of the desiccant. The released heated moisture/humidity mayflow from desiccant assembly 210 through outlet 204 into the washchamber 106, where it may mix with and heat fluid in the wash chamber106.

Additionally, heat generated by the heating unit 255 may facilitateinitial drying of articles during the delay period 322. Such heat may begenerated before the delay period 322 (with the heating unit 255inactive during the delay period 322) or during the delay period 322(with the heating unit 255 active during the delay period 322),depending on the operations of the heating unit 255, fan 250 and/or tubfan 180 during other steps of a method 300 in accordance with thepresent disclosure.

Further, when the heating unit 255 is inactive, relatively moist/humidfluid from the wash chamber 106 may flow into the desiccant assembly 210through inlet 202, and this moisture/humidity may be adsorbed by thedesiccant, which may be at relatively lower temperatures due toinactivity of the heating unit 255.

Accordingly, dishwasher appliances 100 and methods 300 in accordancewith the present disclosure may advantageously provide improved, moreefficient washing and drying of articles.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A method for operating a dishwasher appliance,the method comprising: executing a wet cycle, wherein a heating unit anda fan of a desiccant assembly are active during the wet cycle, thedesiccant assembly comprising the heating unit, the fan, and a desiccantmodule and in fluid communication with a wash chamber of the dishwasherappliance; executing a delay period, the delay period occurring for apredetermined time period between the wet cycle and a dry cycle, whereinthe heating unit and the fan are inactive during the delay period;draining liquid from the wash chamber after the delay period; andexecuting a dry cycle, wherein the fan is active and the heating unit isinactive during the dry cycle.
 2. The method of claim 1, wherein the wetcycle comprises a prewash cycle, a wash cycle and a rinse cycle, andwherein the heating unit and the fan are continuously active during theentire prewash cycle, the entire wash cycle and the entire rinse cycle.3. The method of claim 1, wherein the fan is continuously active and theheating unit is continuously inactive during the entire dry cycle. 4.The method of claim 1, wherein the predetermined time period is between1 minute and 15 minutes.
 5. The method of claim 1, wherein no liquid isdrained from the wash chamber after the wet cycle and before the delayperiod is executed.
 6. The method of claim 1, wherein the heating unitand the fan are inactive during the step of draining liquid from thewash chamber.
 7. The method of claim 6, wherein the heating unit and thefan are continuously inactive during the entire step of draining liquidfrom the wash chamber.
 8. The method of claim 1, wherein a tub fan isactive during the delay period and active during the dry cycle, the tubfan configured to actively flow air within the wash chamber.
 9. Themethod of claim 8, wherein the tub fan is inactive during the wet cycle.10. The method of claim 8, wherein the tub fan is active during the stepof draining liquid from the wash chamber.
 11. The method of claim 1,wherein the desiccant module comprises a granular desiccant.
 12. Adishwasher appliance, comprising: a cabinet defining an interior; a tubdisposed within the interior and defining a wash chamber for the receiptof articles for cleaning; a tub fan, the tub fan positioned within theinterior and configured to actively flow air within the wash chamber; asump for collecting liquid from the chamber; a drain conduit fordraining liquid from the tub; a fluid circulation conduit forcirculating liquid in the tub; and a closed-loop adsorption assembly influid communication with the wash chamber, the closed-loop adsorptionassembly comprising a desiccant assembly, the desiccant assemblycomprising a desiccant module, a heating unit and a fan.
 13. Thedishwasher appliance of claim 12, further comprising a controller, thecontroller in communication with the heating unit and the fan andconfigured for: executing a wet cycle, wherein the heating unit and thefan are active during the wet cycle; executing a delay period, the delayperiod occurring for a predetermined time period between the wet cycleand a dry cycle, wherein the heating unit and the fan are inactiveduring the delay period; draining liquid from the wash chamber after thedelay period; and executing a dry cycle, wherein the fan is active andthe heating unit is inactive during the dry cycle.
 14. The dishwasherappliance of claim 13, wherein the wet cycle comprises a prewash cycle,a wash cycle and a rinse cycle, and wherein the heating unit and the fanare continuously active during the entire prewash cycle, the entire washcycle and the entire rinse cycle.
 15. The dishwasher appliance of claim13, wherein the fan is continuously active and the heating unit iscontinuously inactive during the entire dry cycle.
 16. The dishwasherappliance of claim 13, wherein the predetermined time period is between1 minute and 15 minutes.
 17. The dishwasher appliance of claim 13,wherein the heating unit and the fan are inactive during the step ofdraining liquid from the wash chamber.
 18. The dishwasher appliance ofclaim 13, wherein the controller is further in communication with thetub fan, and wherein the tub fan is active during the delay period andactive during the dry cycle.
 19. The dishwasher appliance of claim 18,wherein the tub fan is inactive during the wet cycle.
 20. The dishwasherappliance of claim 18, wherein the tub fan is active during the step ofdraining liquid from the wash chamber.